The present invention relates to the assessment of psychophysical and physiological responses of a human subject to stimuli delivered to that subject's nose and/or eyes.
Recent interest in air quality has made it desirable to quantify the responses of humans to a wide range of the constituents which can be present in the atmosphere. Some of the constituents of the environmental air may be regarded as pollutants. However, the levels of certain pollutants, irritants or odorants in the atmosphere are oftentimes very low. Thus, it is difficult to reliably present to a human subject such constituents at the concentrations actually present in the environment. Also, it is difficult to fully characterize the responses of human subjects to these constituents using both psychophysical and physiological measurements.
Additionally, recent interest in the development of flavors and fragrances has required efficient and effective means for characterizing particular flavors and fragrances at low levels in environmental air. Such characterization of certain flavors and fragrances is often performed using human subjects. Stordeur et al, J. Air Poll. Cont. Assoc., Vol. 31, p. 377 (1981) propose a microprocessor-controlled dynamic olfactometer. The proposed device reportedly supplies air containing controlled amounts of odorant samples to the nose of a human subject. The human subject then can comment regarding the odorous stimuli which were provided by the air sample. However, the reference does not propose a device which can provide for the measurement of physiological responses (e.g., changes in breathing rate). In addition, the proposed device does not provide stimulus to the eyes of the subject.
Benignus et al, Behav. Res. Meth. & Instr., Vol. 12, p. 535 (1980) propose a computer-controlled vapor dilution olfactometer. However, the reference proposes only providing an air sample to the nose of the human subject.
Laing, Perception, Vol. 12, p. 99 (1983) and Physio. & Behav., Vol. 34, p. 569 (1985) proposes an apparatus for testing the sniffing behavior of human subjects. However, the subject is allowed to sample a gaseous material through his/her mouth.
Cain et al, Atmos. Envir., Vol. 21, p. 347 (1987) proposes applying a sample of environmental tobacco smoke to the face of a subject. The reference does not propose recording physiological responses of the subject.
It would be highly desirable to provide an apparatus for providing controlled samples of air, which contains known concentrations of odorant independently to the eyes and nose of a subject. In addition, it would be desirable to obtain both physiological and psychophysical responses of the subject to the stimulus provided by the air sample.